Updated June 2026
Models failing to load in ComfyUI stops your workflow. This guide offers direct, actionable steps to diagnose and resolve the “ComfyUI model not loading fix” issue.
⚡ Quick fix
- Start with initial checks & common error messages.
- Start with why this happens:.
- Start with steps:.
- Start with model file integrity and location verification.
What this problem means
Models failing to load in ComfyUI stops your workflow. This guide offers direct, actionable steps to diagnose and resolve the “ComfyUI model not loading fix” issue.
1. Initial Checks & Common Error Messages
When ComfyUI fails to load a model, you often see errors like:
Error loading checkpoint: [model_name]FileNotFoundError: [path_to_model]KeyError: 'state_dict' not found in model(less common for path issues, more for corrupted files)
Why this happens:
These errors typically mean ComfyUI cannot find the model file at the expected location, or the file itself is inaccessible or damaged.
Steps:
- Restart ComfyUI: Sometimes, a simple restart clears temporary glitches. Close and reopen your ComfyUI application.
- Verify Model Path: Double-check the path you entered in your workflow. A single typo can prevent loading. Ensure the model name and file extension (e.g.,
.safetensors,.ckpt) are correct. - Check ComfyUI Terminal/Console: The command line interface where ComfyUI runs often provides more detailed error messages than the UI. Look for specific file paths mentioned in the error.
2. Model File Integrity and Location Verification
Incorrect placement or a damaged model file is a frequent cause for models not loading.
Why this happens:
Downloads can be incomplete, files might be moved accidentally, or placed in a non-standard directory that ComfyUI doesn’t automatically scan.
Diagnostic checklist before you escalate
Most web-app failures can be narrowed to service status, one account session, browser data, an extension, or the network. Test those boundaries in order rather than clearing everything at once. A private window and a second network are especially useful because they change one layer without altering your account data.
- Check the provider’s official status page before changing local settings.
- Hard-refresh, start a new session, and test a private browser window.
- Disable content blockers, privacy extensions, VPN, proxy, and secure DNS temporarily.
- Compare another browser, device, and network to locate the failing boundary.
- Record timestamps, error text, and the smallest reproducible sequence for support.
| Test | What the result tells you | Next move |
|---|---|---|
| Official status page reports an incident | The service is affected beyond your device | Pause local resets and monitor recovery |
| Private window works | Normal browser data or an extension is involved | Clear site data and enable extensions one by one |
| Another network works | DNS, VPN, proxy, firewall, or filtering is involved | Review the original network configuration |
| Failure follows the account everywhere | Account, plan, quota, or service-side state is likely | Collect evidence and contact official support |
Verify the recovery across session and network boundaries
When ComfyUI Model Not Loading starts working, repeat the original action in a fresh tab and then in the normal browser profile. Confirm that buttons, uploads, saved history, and live updates behave normally instead of only rendering the first screen. If private mode works but the regular profile fails, continue isolating cookies and extensions rather than declaring the service fixed.
Restore extensions, VPN, proxy, secure DNS, and content filtering one at a time. Reload after each change. This controlled restoration identifies the incompatible layer and prevents the common outcome where everything is disabled permanently. Finish by testing one other device or network so you know whether the recovery belongs to the account, the device, or the connection.
- The original action succeeds twice in a fresh session.
- The normal browser profile works after cleanup.
- Extensions and network controls are restored individually.
- Saved data and account history remain available.
- A second device or network confirms the result.
Keep a short note of the working configuration and the date of the test. Products, models, browser versions, limits, and safety policies change over time, so a previously successful workaround may later become obsolete. Prefer current official documentation over old forum instructions, and reverse temporary diagnostic changes once testing is complete. This gives you a reliable baseline without leaving extensions disabled, security controls weakened, or experimental settings enabled indefinitely. Recheck the baseline after major updates before assuming an older failure has returned for the same reason.
When none of the fixes work
Repeat the smallest failing action once and record the exact local time and time zone. Note the product, model or feature, account plan, browser or app version, operating system, and whether the same action works in a private window, on another device, or on another network. This evidence is much more useful than saying the tool is “still broken.”
Use the provider’s official support channel. Include a screenshot with sensitive information removed and list the steps already tested. For developer tools, add sanitized request and response details, correlation IDs, and SDK versions. Never send passwords, one-time codes, API keys, session cookies, private repository contents, or complete payment information.
FAQ
- Q: Why do models sometimes fail to load after a ComfyUI update?
- A: Updates can sometimes introduce breaking changes, new dependencies, or deprecate old features. Custom nodes might also become incompatible. Always update dependencies (
pip install -r requirements.txt) and check for custom node updates. - Q: Can corrupted model files cause loading errors?
- A: Yes. A corrupted download or a file that’s been partially written can cause parsing errors or
KeyError: 'state_dict' not found. Redownloading the model and verifying its file size/hash is the best fix. - Q: What if I specifically see a “CUDA out of memory” error?
- A: This explicitly indicates you’ve run out of VRAM. Try using smaller models, implementing the
--lowvramor--medvramflags when starting ComfyUI, optimizing your workflow, or closing other applications that consume GPU memory.
Troubleshooting ComfyUI model loading issues typically involves checking file paths, verifying model integrity, and ensuring your system has adequate resources and correct configurations.
Bottom line: Work from the least disruptive test to the most specific one. Confirm service health, isolate session and network variables, then escalate with clean evidence instead of repeating the same failing action.
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